Prognostic value of IL-27 polymorphisms and the susceptibility to epithelial ovarian cancer in a Chinese population

This study investigated the association between IL-27 gene polymorphisms and susceptibility to epithelial ovarian cancer in a Chinese population and discusses the risk factors associated with survival time. We collected data on 229 patients diagnosed with epithelial ovarian cancer, from 15 to 77 years of age with a long clinical follow-up period. Polymerase chain reaction-restriction fragment length polymorphism was performed to determine the genotype of IL-27 gene polymorphisms. Ovarian cancer-specific survival (OCSS) according to genotype of IL-27 gene polymorphisms was explored by Kaplan-Meier analysis and Cox proportional hazards modeling. Significant differences for genotype frequencies of both SNP sites were found between cases and controls. Both allele G frequencies were significantly greater among the cases (rs153109: 0.404 vs. 0.303, P = 0.001, odds ratio [OR] = 1.333, 95% confidence interval [CI] = 1.133-1.567; rs17855750: 0.146 vs. 0.083, P = 0.001, OR = 1.766, 95% CI = 1.258-2.481). Haplotype analysis showed haplotypes AG, GT and GG were associated with increased ovarian cancer susceptibility while AT was a protective haplotype. Advanced FIGO stage (stages III + IV) and non-optimal cytoreductive surgery (residual tumor a parts per thousand yen1 cm) were poor prognostic factors in the univariate analysis (P = 0.003, P = 0.049). However, FIGO stage was found to be the only independent significant prognostic factor by Cox proportional hazards analysis (P = 0.042). IL-27p28 mRNA expression was significantly decreased in ovarian cancer patients (P < 0.0001), while no significant relationship was found between IL-27p28 mRNA expression and polymorphism of rs153109 and rs17855750 (P = 0.193 and P = 0.146, respectively). Our study suggests that IL-27 gene polymorphisms may be involved in the susceptibility to epithelial ovarian cancer, but not in survival in a clinic-based Chinese population. Haplotype analysis of these two SNPs seems to be an important mark to predict the disease susceptibility. Advanced FIGO stage, as the only significant, independent risk factor, predicts poor clinical outcomes for patients diagnosed with epithelial ovarian cancer. The decreased expression of IL-27p28 mRNA in ovarian cancer might indicate the antitumor activities of this novel cytokine.